文章摘要
3,6,6-三甲基-2,4-环庚二烯酮的制备
Preparation of 3,6,6-trimethylcyclohepta-2,4-dienone
投稿时间:2018-11-22  修订日期:2019-03-12
DOI:
中文关键词: 3-蒈烯,3,6,6-三甲基-2,4-环庚二烯酮,CrO3,烯丙位氧化,3-蒈烯-5-酮
英文关键词: 3-carene  3,6,6-trimethylcyclohepta-2,4-dienone  CrO3  allylic oxidization  car-3-ene-5-one
基金项目:江苏省生物质能源与材料重点实验室基本科研业务费项目(JSBEM-S-201709)
作者单位E-mail
王婧 中国林业科学研究院林产化学工业研究所 njwj8324@163.com 
曾小静 中国林业科学研究院林产化学工业研究所  
董欢欢 中国林业科学研究院林产化学工业研究所  
徐士超 中国林业科学研究院林产化学工业研究所  
蒋建新 北京林业大学  
赵振东 中国林业科学研究院林产化学工业研究所 zdzhao@189.cn 
摘要点击次数: 28
全文下载次数: 0
中文摘要:
      CrO3在3-蒈烯氧气氧化反应中具有良好的催化活性,将CrO3通过浸渍法负载于中性氧化铝上,制备得到CrO3-Al2O3,负载率为39.21%,负载后催化剂保留有CrO3的良好性能,并且有助于减少铬元素的残留。反应以烯丙位氧化为主,无环氧化发生,主要生成3种α,β-不饱和酮,分别为3-蒈烯-2-酮、2-蒈烯-4-酮及3-蒈烯-5-酮。分别考察了催化剂用量、温度、时间以及氧气流量对氧化反应的影响,得到最佳氧化工艺为:CrO3-Al2O3用量为3-蒈烯质量的3%、温度25℃、时间10h以及氧气流量25mL/min,对应原料转化率58.72%,α,β-不饱和酮类化合物总选择性86.07%,3-蒈烯-2-酮选择性19.83%、2-蒈烯-4-酮选择性4.61%、3-蒈烯-5-酮选择性61.63%;在减压精馏分离氧化产物过程中,3-蒈烯-5-酮极易异构转化为3,6,6-三甲基-2,4-环庚二烯酮,一步实现了该产物的制备与提纯,但是3-蒈烯-2-酮和2-蒈烯-4-酮不发生类似异构。研究结果证明减压是异构发生的必要条件,而且压力值越小,反应越容易进行且效果越好。0.5kPa压力下,120℃反应4h,3-蒈烯-5-酮转化率99.62%,3,6,6-三甲基-2,4-环庚二烯酮选择性98.15%,表明压力达到0.5kPa即可满足反应要求。
英文摘要:
      CrO3 did a favorable performance in catalyzing oxidation reaction of 3-carene and oxygen. CrO3-Al2O3 with a loading rate of 39.21% was prepared from CrO3 and neutral Al2O3 by impregnation, which not only performed as well as CrO3, but also benefited in reducing the residual quantity of Cr in the reaction solution. Allylic oxidization dominated the reaction and hardly any epoxidation was happened, so three different α,β-unsaturated ketones were produced as main products, that were car-3-ene-2-one, car-2-ene-4-one and car-3-ene-5-one respectively. Many reaction factors were investigated for their effects on the reaction, including catalyst amount, temperature, time and oxygen flux. After a series of condition experiments, the optimum oxidation process was established as that catalyst amount was 3% of the mass of 3-carene, temperature was 25℃, time was 10h and oxygen flux was 25mL/min. By the optimum process a result was obtained with a conversion of 58.72% for raw material and a selectivity of 86.07% for the total α,β-unsaturated ketones, while 19.83% for car-3-ene-2-one, 4.61% for car-2-ene-4-one and 61.63% for car-3-ene-5-one respectively. During the separation of the oxidation product by vacuum rectification, car-3-ene-5-one was found to be very easily isomerized and converted, as which preparation and separation of 3,6,6-trimethylcyclohepta-2,4-dienone could be accomplished in one step. However, similar isomerization reactions were not happened for car-3-ene-2-one and car-2-ene-4-one in this process. Results showed that reduced pressure was a necessary condition for isomerization, and the lower the pressure, the easier the reaction would occur, and the higher the effect would be. A conversion of 99.62% for car-3-ene-5-one and a selectivity of 98.15% for 3,6,6-trimethylcyclohepta-2,4-dienone could be obtained while the pressure was 0.5kPa, temperature was 120℃ and time was 4h, which indicated that a pressure of 0.5 kPa completely satisfied the reaction requirement.
View Fulltext   查看/发表评论  下载PDF阅读器
关闭